Abstract

In order to cope with the explosive growth of the mobile data traffic, it's been proposed the concept of Small Cells, telephony cells with great capacity. To implement them, it's been proposed a backhaul network composed of up to 20 nodes interlinked by mesh Wi-Fi. All nodes offer an access point to the user, however, only some of them must be connected by wire to the base station, which connects to the core network. Despite the merit of the IEEE 802.11s protocol of distributing the routing decisions, it is unable to detect bottlenecks and lacks a global vision of the whole network that would enable more intelligents decisions. By adapting the Software Defined Networking technologies to the wireless environment, we become able to gather in a single point all the information of occupation, quality and load of all the links between nodes. This allows to lighten the wireless nodes, that run Open vSwitch (SDN agent), and concentrate all the computational effort in a single machine running OpenDaylight (SDN controller), hosted in a data center. Following the previous work, we have deployed a testbed of RaspberryPi-based nodes with two Wi-Fi dongles each, taking into account the power consumpiton, the stability along the time, and the computational load. We have implemented the collection of statistics about congestion indicators, organized a strong configuration system for the nodes, and, in general, transformed a proof-of-concept into a working testbed for developing intelligent routing algorithms.